Question

Which of the following statements are correct?

(a) PIN register of a port is used to bring data into CPU from pins

(b) PORT register is used to send data out to pins

(c) DDR register is used to control the direction of a port

(d) All of the mentioned

I had been asked this question by my college director while I was bunking the class.

Asked question is from I/O Port Programming and Addressing Modes topic in portion AVR Microcontroller of Microcontroller

Answer 1

The correct option is (d) All of the mentioned

Easiest explanation: There are three registers that are related to a port. They are PIN, PORT, DDR. PIN register is used to bring data into CPU from pins, PORT register is used to send data to pins and DDR register is used to control the direction of the data transfer. So all are the right options.